ABSTRACT Advance care planning (ACP), including end-of-life (EOL) discussions and decision-making, are important elements for the care of chronically and critically ill patients. Alzheimer's disease and its related dementias (AD/ADRD) represent a class of illnesses that impact independent decision making potentially far in advance of other more obvious aspects of illness and frailty. Patients with AD/ADRD may not recognize their cognitive decline and loss of capacity. In the absence of designated proxies or alert practitioners, such individuals may experience care that is inconsistent with their wishes (as they would have been able to otherwise compose or express). Thus, individuals with AD/ADRD may experience (1) unwanted delays in eliciting accurate expressions of their wishes relative to those without AD/ADRD and (2) inability to complete POLST and related forms even when proxies are available. Small studies examining ACP in AD/ADRD have lacked sufficient power to address pressing questions regarding the timing, adequacy, adherence, and disparities in POLST use and in resultant care among individuals with AD/ADRD. Early reporting on use among California nursing home residents suggests significant differences in POLST completion and intensity of care preferences related to levels of cognitive function: paradoxically more cognitive impairment is associated with less POLST completion. Mediating factors ? proxy availability, comorbidity, functional status, and social support (including marriage status and proximity to home) ? are unexplored regarding POLST completion. Since that early work, no further work has examined whether diffusion of POLST adoption over time has diminished observed differences. The impact of POLST is exceedingly important in patients with AD/ADRD. We propose in this administrative supplement to examine POLST implementation among individuals with AD/ADRD residing in nursing homes in California and to compare the intensity of acute care for patients with AD/ADRD between two states ? California (where POLST implementation is mature and reported in the Minimum Data Set) and Texas (where POLST implementation is early and occurs primarily in pilot projects) ? between the years 2011 to 2015, with the following specific aims: 1. Determine dependence and frailty in the AD/ADRD population in nursing homes in the two states. 2. Examine differences in quality and intensity of acute care among individuals with AD/ADRD in California and Texas. 3. In California, examine among patients with AD/ADRD POLST completion, treatment preferences contained in POLST, and receipt of care among patients with and without a POLST and receipt of care concordant with POLST preferences when POLST is completed by the patient or is completed by a proxy, including underlying trends between 2011 and 2015.